You can easily install Server Backup Manager from inside WHMCS.
WHMCS Top menu -> Addons -> Jetbackupmanager
From Jetbackupmanager, navigate to “Easy deployment” tab and select “Clean install”.
You will to select servers for the installation, server list is generated from WHMCS Top menu -> Setup -> Product Services -> Servers. You can install JBM into a single server, or multiple servers at once.